Currently, thin film transistor liquid crystal display (TFT-LCD) is mainly used in a display product. An advanced super dimension switch (ADS) technique has been widely used in various display products due to its advantages such as high resolution, high light transmittance, low power consumption, wide viewing angle, high aperture ratio, low chromatic aberration, and being free of push Mura. Its core features may be described as forming a multi-dimensional electric field by means of electrical fields generated at edges of slit electrodes within an identical plane and an electrical field generated between a slit electrode layer and a plate electrode layer, so as to enable all the liquid crystal molecules between the slit electrodes and right above the electrodes within a liquid crystal cell to rotate, thereby to improve the operational efficiency of the liquid crystal molecules and enhance the light transmission efficiency.
Optical efficiency is one of the principal factors that may affect a LCD display effect. Depending on a phase delay of a liquid crystal unit, its display effect may be determined by the optical efficiency, which is expressed as d×Δn, where d represents a thickness of a liquid crystal layer between an upper substrate and a lower substrate of a liquid crystal display panel, and Δn represents a birefringence difference of liquid crystals. At an initial white-light level, white light beams may be viewed by human eyes. When it is shifted gradually to a middle grayscale and the red-light transmittance increases, a color of the LCD viewed by the human eyes is not white any more, and instead, chromatic aberration slightly shifted toward yellow may occur. The so-called “yellowish” phenomenon is just one of the principal causes for the deterioration in the image quality of the display.
During the manufacture of the liquid crystal display panel, there is inevitably a certain pretilt angle of the liquid crystal layer relative to a surface of an alignment layer due to a rubbing alignment process (i.e., it is impossible for the pretilt angle of the liquid crystal layer to be 0°). At this time, when a left viewing angle is identical to a right viewing angle, liquid crystal axial directions viewed at the left viewing angle and the right viewing angle are different from each other, thereby Δn for the left viewing angle is different from that for the right viewing angle. Because d is of an identical value when the left viewing angle is identical to the right viewing angle, the phase delay Δn×d for the left viewing angle is different from that for the right viewing angle, and different optical path differences may occur. At this time, the light beams transmitted through liquid crystal display panel may be of different wavelengths, resulting in the chromatic aberration, which is more apparent in a dark state. As a result, the display effect of the liquid crystal display panel will be adversely affected.